The invention relates to a method of observing a multitude of objects which move in a space monitored by several sensors, wherein the objects are detected by the sensors and are followed under continuing actualization by sensor tracks that supply object data; and wherein, from the available sensor tracks, those sensor tracks which originate from different sensors and which belong to the same object, are automatically associated with a system track.
Floating platforms, such as surface vessels, are provided with a multitude of various sensors for reconnoitering and monitoring the sea area about the platform as well as the air space thereabove. The sensors deliver measuring results, termed as tracks, concerning the detected objects and continuously update the tracks at time intervals, designated as updating the tracks. Examples of such sensors are navigational radar, long and short range monitoring radar, electro-optical equipment with laser distance measurement, etc. By a track there is meant a set of object data which indicates the position and the velocity vector (the so-called kinematics) of the object as well as classification attributes of the object.
For observing the behavior of the individual objects, the tracks of the individual sensors, termed as sensor tracks, have to be brought together and displayed for an operator in a manner as clearly as possible on a position map which cartographically represents the monitoring space. For this purpose the earlier-noted process associates the tracks of the different sensors (that is, the sensor tracks), inasmuch as they relate to the same object, with a system track which determines the representation of the object on the position map.
According to the earlier-outlined processes, for this purpose always an unequivocal decision of association (positive or negative) has been made and the validity of the decisions has been verified either in fixed time intervals or by updating the sensor tracks. The number of computing operations increases quadratically with the number of the available sensor tracks. Thus, in case of a large number (for example, 1000) objects, a substantial computer capacity is required which would no longer be available for other purposes.
It is an object of the invention to improve a process of the earlier-mentioned type in such a manner that the decision of association is made particularly efficiently, reliably and substantially fully automatically, that is, without an operator's intervention, and further, that it is adapted for the simultaneous handling of a large number of objects with the simultaneous reduction of requirements as concerns computer capacity.